RtLogs.follow() + unit test

src/main/java/com/amihaiemil/docker/ReadJsonArray.java

@@ -35,7 +35,7 @@
  * Handler that reads a JsonArray from the response.
  * @author Mihai Andronache (amihaiemil@gmail.com)
  * @version $Id$
- * @since 0.0.
+ * @since 0.0.1
  * @todo #84:30min Write some unit tests for this class, it is
  *  currently only tested by RtImagesITCase#iteratesImages.
  */

src/main/java/com/amihaiemil/docker/ReadJsonObject.java

@@ -35,7 +35,7 @@
  * Handler that reads a JsonObject from the response.
  * @author Mihai Andronache (amihaiemil@gmail.com)
  * @version $Id$
- * @since 0.0.
+ * @since 0.0.1
  */
 final class ReadJsonObject implements ResponseHandler<JsonObject> {
 

src/main/java/com/amihaiemil/docker/ReadLogsStream.java

@@ -0,0 +1,61 @@
+/**
+ * Copyright (c) 2018, Mihai Emil Andronache
+ * All rights reserved.
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * 1)Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ * 2)Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ * 3)Neither the name of docker-java-api nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+package com.amihaiemil.docker;
+
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import org.apache.http.HttpResponse;
+import org.apache.http.client.ResponseHandler;
+
+/**
+ * Handler that returns the stream response as a Reader.
+ * @author Mihai Andronache (amihaiemil@gmail.com)
+ * @version $Id$
+ * @since 0.0.2
+ */
+final class ReadLogsStream implements ResponseHandler<Reader> {
+
+    /**
+     * Handlers to be executed before actually reading the array.
+     */
+    private final ResponseHandler<HttpResponse> other;
+
+    /**
+     * Ctor.
+     * @param other Handlers to be executed before actually reading the array.
+     */
+    ReadLogsStream(final ResponseHandler<HttpResponse> other) {
+        this.other = other;
+    }
+
+    @Override
+    public Reader handleResponse(final HttpResponse httpResponse)
+        throws IOException {
+        final HttpResponse resp = this.other.handleResponse(httpResponse);
+        return new InputStreamReader(resp.getEntity().getContent());
+    }
+}

src/main/java/com/amihaiemil/docker/RtLogs.java

@@ -28,16 +28,22 @@
 import java.io.IOException;
 import java.io.Reader;
 import java.net.URI;
+import org.apache.http.HttpStatus;
 import org.apache.http.client.HttpClient;
+import org.apache.http.client.methods.HttpGet;
 
 /**
  * Restful container logs.
  * @author Mihai Andronache (amihaiemil@gmail.com)
  * @version $Id$
  * @since 0.0.2
- * @todo #128:30min Continue implementing this class (fetch and follow) and also
+ * @todo #130:30min Continue implementing this class (method fetch) and also
  *  take into consideration the query parameters as described here:
  *  https://docs.docker.com/engine/api/v1.35/#operation/ContainerLogs
+ * @todo #130:30min Write some ITCase for the fetch() method. We might have to
+ *  implement the stream decoding (in case TTY is disabled when the Container
+ *  is created), as explained here, in "Stream format" paragraph:
+ *  https://docs.docker.com/engine/api/v1.37/#operation/ContainerAttach
  */
 final class RtLogs implements Logs {
 
@@ -79,9 +85,19 @@ public String fetch() throws IOException, UnexpectedResponseException {
     @Override
     public Reader follow()
         throws IOException, UnexpectedResponseException {
-        throw new UnsupportedOperationException(
-            "Operation not yet implemented. If you can contribute please,"
-            + " do it here: https://www.github.com/amihaiemil/docker-java-api"
+        final HttpGet follow = new HttpGet(
+            new UncheckedUriBuilder(this.baseUri.toString())
+                .addParameter("follow", "true")
+                .build()
+        );
+        return this.client.execute(
+            follow,
+            new ReadLogsStream(
+                new MatchStatus(
+                    follow.getURI(),
+                    HttpStatus.SC_SWITCHING_PROTOCOLS
+                )
+            )
         );
     }
 

src/test/java/com/amihaiemil/docker/RtLogsTestCase.java

@@ -25,7 +25,14 @@
  */
 package com.amihaiemil.docker;
 
+import com.amihaiemil.docker.mock.AssertRequest;
+import com.amihaiemil.docker.mock.Condition;
+import com.amihaiemil.docker.mock.Response;
+import java.io.BufferedReader;
 import java.net.URI;
+import java.util.stream.Collectors;
+import javax.json.Json;
+import org.apache.http.HttpStatus;
 import org.apache.http.client.HttpClient;
 import org.hamcrest.MatcherAssert;
 import org.hamcrest.Matchers;
@@ -57,4 +64,40 @@ public void getsContainer(){
         );
     }
 
+    /**
+     * RtLogs can follow the Container's logs (return a Reader of the stream).
+     * @throws Exception If something goes wrong.
+     */
+    @Test
+    public void followsLogs() throws Exception {
+        final Logs logs = new RtLogs(
+            Mockito.mock(Container.class),
+            new AssertRequest(
+                new Response(
+                    HttpStatus.SC_SWITCHING_PROTOCOLS,
+                    Json.createObjectBuilder()
+                        .add("logs", "...some logs...")
+                        .build().toString()
+                ),
+                new Condition(
+                    "Method should be a GET",
+                    req -> req.getRequestLine().getMethod().equals("GET")
+                ),
+                new Condition(
+                    "Resource path must be /123/logs?follow=true",
+                    req -> req.getRequestLine().getUri().endsWith(
+                        "/123/logs?follow=true"
+                    )
+                )
+            ),
+            URI.create("http://localhost:80/1.30/containers/123/logs")
+        );
+        try (final BufferedReader bfr = new BufferedReader(logs.follow());) {
+            MatcherAssert.assertThat(
+                bfr.lines().collect(Collectors.joining("\n")),
+                Matchers.equalTo("{\"logs\":\"...some logs...\"}")
+            );
+        }
+    }
+
 }